The present invention relates to a laminated panel comprising at least two sheet members, and in particular to a laminated panel for a diaper cover, disposable diaper, sanitary napkin, urine-absorbent pad and the like.
Japanese Patent Application Disclosure No. 1996-196559 discloses a disposable diaper comprising a liquid-permeable topsheet, a liquid-impermeable backsheet and a liquid-absorbent core interposed between the topsheet and the backsheet. The core formed of a liquid retaining layer and a fiber assembled layer is covered with tissue paper (water-permeable sheet), and the core and the tissue paper are joined by means of hotmelt adhesive substantially in the entire area of the surface at which the core and the tissue paper overlap with each other. The application pattern of the adhesive includes a dot-like application pattern formed with a plurality of straight continuous dot-like lines extending in one direction; a vertical stripe application pattern formed with a plurality of straight lines extending in one direction; a grid-like application pattern formed with straight lines extending while intersecting with each other; and a spiral application pattern formed with a plurality of curved lines extending while intersecting with themselves.
The adhesive applied in the dot-like pattern or the vertical stripe pattern can prevent delamination between the core and the tissue paper with respect to the direction perpendicular to the direction in which the adhesive extends. However, with respect to the direction in which the adhesive extends, delamination between the core and the tissue paper is prevented just at points, so that the core and the tissue paper may easily be delaminated in the direction in which the adhesive extends.
In order to reinforce the adhesive strength, it is preferable to apply the adhesive in the grid-like pattern or in the spiral pattern. However, at the points where the adhesive intersects with other adhesive or itself, the adhesive is applied one upon another, resulting that the application amount of the adhesive is increased compared to the portion where the adhesive does not intersect with other adhesive or itself. At the intersecting points, the adhesive having soaked into the tissue paper will close fiber gaps of the tissue paper over a wide area. Accordingly, if the number of intersecting points is too large, the adhesive will sometimes prevent the liquid permeability of the tissue paper.
It is an object of the invention to provide a laminated panel in which an adhesive is applied so that delamination is unlikely to occur in a direction in which the adhesive extends as well as in a direction intersecting the direction comprising the adhesive extends, and liquid permeability possessed by sheet members will not be prevented.
A laminated panel of the present invention comprises at least two sheet members overlapped with and joined to each other by means of adhesive applied on at least one of inner surfaces of the sheet members, wherein the adhesive forms a plurality of separated adhesive lines extending in one direction while being bent; the number of times in which one of the adhesive lines repeats bending is in the range of 50 to 200 per 1 m of the sheet member; the number of times in which one of the adhesive lines intersects is in the range of 0 to 200 per 1 m of the sheet member.
In the present invention xe2x80x9cbendingxe2x80x9d or xe2x80x9cbentxe2x80x9d involves the case where the adhesive line extends in a zigzag pattern while being bent; the case where the adhesive line extends in a wave shape while rising and falling; and the case where the adhesive line extends in a square wave shape while picturing bumps and dips.
In the laminated panel constituting the body fluid disposal article, since the adhesive does not prevent the liquid permeability of the topsheet and the water permeability of the tissue paper, body fluids can be smoothly transferred from the topsheet to the tissue paper, and then from the tissue paper to the core, with the result that it is possible to sufficiently utilize the liquid absorptivity possessed by the core.